Here’s some info on power draw. I’m currently printing in ABS (240 C hotend, 110 C bed) using a 2009 iMac to feed data with the screen dimmed to lowest setting but not off. According to my UPS, this system is drawing just over 200 watts. My power is pretty cheap, about a dime per Kwhr, so the 4.25 hour print job will cost me 8.5 cents in electricity, use 72g of filament (95% fill rate so this is somewhat high) at about 2.5c/g – about $1.80, or $1.885 for juice and plastic. That’s $0.449/hr. I don’t want to stop the job to figure out what the computer draws on its own, but certainly a beaglebone or raspPi would decrease the power needs, but with such cheap power, it might take a long time to make that up.
Based on just material and electricity, $1/hr would be an amazing bargain. But then you need to consider the printer cost. At $1350, if you ran it 40hr/wk at $1/hr, it would take almost 34 weeks to recoup that cost excluding electricity and filament. Add in the filament and electricity used over 1350 hrs at 44.9c/hr, you get $606.15. The next 650 hours will cost you $291.85 in elec/fil. If your assumption of 2000 hours is correct, and you don’t spend another penny on the printer for maintenance items, that’s 1350+606.15+291.85=$2248. You’d spend almost a year losing $250. You’d have to charge $1.124/hr to break even. Notably, these figures ignore sales tax on the stuff you buy.
I only have experience with one makerspace, but I found the costs at the one near me to be so high that it made it ridiculously economical to buy my own printer. They charge a memebership fee of $50/mo (or a 3 day pass for $20), and then $0.25/g for filament. The $1.80 in plastic I’m printing right now would cost $18.00, and you have to pay for failed prints, brim, and support material too. The event the pushed me into buying my own printer was spending 13 hours on Saturday at the space – twice a printer glitch ruined my print. I spent $20 in plastic plus $50 for the membership and got nothing at all. Yes, I could have gone back more that month, so it isn’t exactly fair to say it was $70 for nothing but garbage, but between the conflicts with my schedule, their hours, and printer availability, I wouldn’t have gotten much more value for my membership and I would have paid through the nose for filament. At 25c/g, a spool of filament is $250.
Anyway, let’s say that I can drop everything and devote 10hrs/wk to being at the makerspace(*) (**), that’s 43 hrs/month, or $1.16/hr in membership fees. Using this print job printing 17g/hr, at 25c gm, that’s $4.25/hr in material costs, total is $5.41/hr.
Using 2000 hours and a perfectly running Mini again, and my $5.41/hr cost, they gross $10,800 on users like me, spend $898 in electricity/filament, and $1350 on printer (actually there’s sales tax too, but let’s forget about that for now): That’s a net of $8552. To be fair, there’s also all the costs in paying for a building, staff, taxes, etc. We’ll leave that out.
So, at $1/hr you are losing money, $1.124 breaking even, and at $5.41/hr, you’re basically telling your customers to get their own printer. Somewhere inside that range, you might find a figure that makes sense, providing this is either a garage based business which doesn’t require any additional layout for building costs, or you do a big volume business and have a couple dozen printers chugging away 24/7.
- This assumes no scheduling conflicts with the printer. The lower this number, the higher my per hour membership costs.
** I love that with a printer at home, I can start a print and go mow the lawn. I can’t do that if trapped at the makerspace.